Cytogenetic Studies of B-cell Chronic Lymphocytic Leukemia (B-CLL)

B 细胞慢性淋巴细胞白血病 (B-CLL) 的细胞遗传学研究

• 批准号: 7969821
• 负责人: diane c arthur
• 金额: $ 19.65万
• 依托单位: DIVISION OF CLINICAL SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7969821
• 关键词: 11q; 13q; 14q32; Abnormal Cell; Address; B-Lymphocytes; Blood Cells; Chromosomal Loss; Chromosome abnormality; Chronic Lymphocytic Leukemia; Clinical; Clinical Research; Conflict (Psychology); Cytogenetics; DNA; DNA Sequence Rearrangement; Data; Detection; Diagnosis; Diagnostic Procedure; Disease; Disease Outcome; Evaluation; Fluorescent in Situ Hybridization; Frequencies; G-Banding; Gene Expression; Genetic; In Vitro; Interphase; Karyotype; Laboratories; Leukemic Cell; Lipopolysaccharides; Metaphase; Microarray Analysis; Mitogens; Mitotic; Molecular Cytogenetics; Outcome; Patients; Prospective Studies; Reporting; Series; Specificity; Techniques; Technology; Testing; Time; Trisomy 12; Variant; cDNA Arrays; comparative genomic hybridization; disease characteristic; prognostic

Previous G-banded karyotype analyses have detected clonal chromosome abnormalities in 40-100 percent of B-CLL patients studied after appropriate in-vitro stimulation with polyclonal B-cell mitogens. It is currently unknown whether the wide variations in frequencies of abnormalities reported in different series are due to true differences in disease characteristics or merely to in-vitro culture conditions. Common recurring chromosomal abnormalities include trisomy 12, rearrangements of 14q32, translocations or deletions of 13q, deletions of 6q, and deletions of 11q. Recent studies have shown increased detection of trisomy 12, 13q deletions and 11q deletions with interphase fluorescence in-situ hybridization (FISH) techniques, suggesting these changes do indeed occur early in the course of the disease. Data regarding the clinical and prognostic significance of karyotype in B-CLL are limited, and in some instances are conflicting. Nevertheless, preliminary clinical studies suggest certain karyotypic abnormalities are associated with specific clinicopathologic subsets of B-CLL, and with the course of the disease. To address the questions of timing of karyotypic changes in B-CLL, and the possible specificity and significance of these changes, we are conducting prospective studies of patients with sporadic or familial B-CLL referred to the NCI for evaluation and possible treatment. The cytogenetics specific aims of this project are: to determine the optimal culture conditions for obtaining karyotypically abnormal mitotic cells from peripheral blood of patients with B-CLL; to determine whether or not interphase FISH detects clonally abnormal cells missed by G-banded metaphase analysis; to determine whether or not comparative genomic hybridization (CGH) will detect gains or losses of chromosomal material not found by metaphase or FISH analyses; and to correlate cytogenetics results with clinical, morphologic and immunophenotypic features of the disease, with cDNA microarray analysis of gene expression, and with outcome with new therapies. Data from >120 patients entered on-study reveal clonal chromosome abnormalities in only 30 percent of cases using G-banded metaphase analysis, and demonstrate inferiority of e. coli lipopolysaccharide as a mitogen for the leukemic cells. Interphase FISH with a panel of five probes has confirmed or expanded the G-band findings in patients with abnormal clones, and has detected abnormalities in all but 10 patients tested to date who were "normal" or uninformative by G-banding. From 2002 through 2005 we performed CGH retrospectively on DNA isolated from patients previously entered on-study, and prospectively on DNA from new patients. CGH was less sensitive than interphase FISH in detecting submicroscopic deletions, but detected gains and losses of regions not probed by FISH. Combining G-banding, FISH, and CGH, we are able to find molecular cytogenetic abnormalities in more than 90% of B-CLL patients. Furthermore, dual hybridization with two probes and also sequential analyses in multiple patients have shown certain abnormalities present at diagnosis, and additional abnormalities at the time of transformation. The cytogenetics results are now being correlated with clinical and other laboratory features at diagnosis and transformation, and with cDNA microarray analysis of gene expression and outcome with treatment. This project, which has the potential to yield new information regarding clinical cytogenetics diagnostic techniques, to demonstrate new clinicopathologic subsets of B-CLL patients, and to define genetic rearrangements critical to initiation or progression of B-CLL, is ongoing.

以前的G显带核型分析已经发现了克隆染色体异常， 40- 100%的B-CLL患者在适当的体外刺激后研究， 多克隆B细胞分裂原。目前尚不清楚频率的广泛变化是否 不同系列报告的异常是由于疾病的真实差异 特征或仅限于体外培养条件。常见重复染色体 异常包括12三体，14 q32重排，13 q易位或缺失， 6 q缺失和11 q缺失。最近的研究表明， 间期荧光原位杂交检测12三体、13 q缺失和11 q缺失 （FISH）技术，表明这些变化确实发生在早期的过程中， 疾病关于B-CLL核型的临床和预后意义的数据如下： 有限，在某些情况下是相互矛盾的。尽管如此，初步的临床研究 提示某些核型异常与特定临床病理 B-CLL的亚群，以及疾病的病程。为了解决时间问题， B-CLL的核型变化，以及这些变化的可能特异性和意义， 我们正在对散发性或家族性B-CLL患者进行前瞻性研究， NCI进行评估和可能的治疗。该项目的细胞遗传学具体目标 确定获得核型异常有丝分裂细胞的最佳培养条件 B-CLL患者外周血中的细胞;以确定间期 FISH检测G带中期分析遗漏的克隆异常细胞;以确定 比较基因组杂交（CGH）是否能检测出 中期分裂相或FISH分析未发现染色体物质;并与细胞遗传学相关 结果与临床，形态学和免疫表型特征的疾病，与cDNA 基因表达的微阵列分析，以及新疗法的结果。数据从 >120名参加研究的患者中，仅30名显示克隆性染色体异常。 %的病例使用G显带中期分析，并证明e.杆菌 脂多糖作为白血病细胞的有丝分裂原。间期FISH，一组5个 探针证实或扩大了异常克隆患者的G带发现， 在所有患者中检测到异常，但迄今为止检测的10名患者为“正常”或 G显带的信息从2002年到2005年，我们回顾性地对DNA进行了CGH 从先前进入研究的患者中分离，并前瞻性地从新的 患者CGH在检测亚显微缺失方面不如间期FISH敏感， 但检测到FISH未探测到的区域的增益和损失。结合G显带、FISH和 CGH，我们能够发现超过90%的B-CLL分子细胞遗传学异常 患者此外，用两个探针的双重杂交和在细胞中的连续分析也是可行的。 多名患者在诊断时表现出某些异常， 变形时的异常。细胞遗传学的结果现在正与 在诊断和转化时具有临床和其他实验室特征， 基因表达和治疗结果的微阵列分析。这个项目， 可能产生关于临床细胞遗传学诊断技术的新信息， 展示B-CLL患者的新的临床病理亚群，并定义遗传 对于B-CLL的开始或进展至关重要的重排正在进行中。